Builders

UTXO and eUTXO

A mental model for transactions that consume complete inputs and create new outputs.

Last reviewed 2026-07-20 · Optional, not assessed

Keep these distinctions

✓Value is not edited in place.
✓Smart-contract conditions can govern which new transaction is valid.

The envelope model

Think of each unspent output as a sealed envelope containing value and conditions. A transaction opens eligible envelopes completely and creates a new set. This explains why wallets may need change outputs and why funding details live in operational docs.

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